The present invention relates generally to connectors for terminating multiple conductors, and more particularly to a connector assembly for selectively terminating multiple conductors and having a structure that permits dual termination of selected conductors, common grounding and isolation of differential signal conductors.
Many electronic devices, especially computers, utilize additional electronic devices which are known in the art as "peripherals". Examples of these peripheral devices are disk drives, CD-ROM drives, digital video disk ("DVD") drives, modems, network adapters, and the like and these peripheral devices utilize power wires and a plurality of signal wires to connect to the computer. These devices utilize ribbon cable for the signal wires for ease of connection to the many associated circuits on the motherboard of the computer.
Ribbon cable consists of a plurality of wires that are formed together as a single extent where the wires are formed together in side-by-side order. The individual conductors of the ribbon cable are surrounded by a flexible insulation. These conductors are spaced close together along the width of the cable and include specific signal and ground conductors corresponding to specific circuits of the peripheral device. In order to terminate such conductors, insulation displacement type terminals ("IDT") are used.
IDT type connectors for ribbon cable include an insulative housing, a mating face for mating with another, complementary conductor, an appropriate cable-receiving face and at least two rows of terminal-receiving passages extending between the two faces. Conductive terminals are received in the passages and each such terminal has a mating portion that extends into the mating face and a U-shaped or a V-shaped insulation displacement portion extending into the cable-receiving face of the connector. A cover is provided to maintain the conductors of the cable into contact with the insulation displacement portions of the terminals.
One problem that occurs with such IDT connectors is a function of the close density of the conductors in the ribbon cable, such as in instances where the wires are spaced on a 0.025 inch pitch. This close spacing of the conductors requires that the insulation displacement portions of the terminals be arranged in two spaced-apart rows wherein the terminals in each row are offset from each other to define, in effect, four rows of staggered IDTs along the cable-receiving face, with adjacent terminals of the connector being located in two distinct rows on the mating face of the connector. Hence, these type of connectors are often referred to as "dual row" connectors in the art. A conductor that will be terminated in either of the rear rows will have to necessarily pass between two insulation displacement terminals of the two forward rows along the cable-receiving face. This close spacing creates problems and may result in shorting where the rear row conductor inadvertently contacts and is pierced by one of the forward IDTs.
One solution to this problem is to modify the physical structure of the connector housing, rather than the structure of the terminals and utilize what is known as a "hill and dale" system to locate adjacent conductors in the IDTs at different vertical levels. This modification of the connector housing complicates the molding of the connector housing and adds to cost of the connector.
Additionally, in these type of IDT systems with dual row terminals, the contact portions of the IDTs are arranged on different sides of the connector mating face. These systems require alternating termination of the first side and then the second side contact portions for successive adjacent conductors in the ribbon cable. This alternating termination must be followed in order to avoid termination of conductors of unfavorable signal types positioned in areas detrimentally affecting differential pairs of signal conductors. The alternating termination must be maintained and therefore detail must be taken in arranging the termination of the conductors to the IDTs to avoid having the unfavorable ground-type signal wires positioned in a manner that will detrimentally affect the signals carried by the differential pairs of signal conductors.
A need therefore exists for an improved connector in which conductors are easily aligned with the respective terminals of the connector and which permits dual termination of certain conductors and which permits differential wire isolation.